CVE-2026-49382: IntelliJ IDEA Copyright Plugin Template Injection RCE

Technical summary

CVE-2026-49382 is a template injection vulnerability in the Copyright plugin bundled with JetBrains IntelliJ IDEA versions prior to 2026.1. The vulnerability allows arbitrary code execution with the privileges of the user running the IDE. The attack vector is local, requires user interaction to trigger (opening a project containing malicious templates), and has a CVSS 3.1 score of 4.5 (MEDIUM). The CWE classification as CWE-1336 (Improper Neutralization of Special Elements in Data Query Logic) indicates insufficient sanitization of template input before processing.

Business impact

Developers whose machines are compromised could have their source code, credentials, and build artifacts stolen or modified. In organizations where multiple developers share project repositories or CI/CD systems, a single malicious project could cascade to compromise the entire supply chain. Intellectual property theft and the insertion of backdoors into production code are realistic concerns. Teams relying on IntelliJ IDEA for Java, Kotlin, or other development workflows need to treat this as a supply-chain hygiene issue.

Affected systems

JetBrains IntelliJ IDEA versions before 2026.1 are affected. The vulnerability resides in the Copyright plugin, which is typically enabled by default. Any developer actively using IntelliJ IDEA in the affected version range is at risk if they open projects from untrusted or insufficiently vetted sources.

Exploitability

The attack requires local machine access and relies on social engineering or supply-chain compromise (e.g., a malicious project on GitHub or a shared repository). The barrier to exploitation is moderate—an attacker cannot trigger this remotely or without the developer explicitly opening a project. However, once the IDE processes the malicious template, code execution is automatic. The vulnerability is not listed on CISA's Known Exploited Vulnerabilities catalog, suggesting active exploitation in the wild has not been publicly documented, but the relative ease of weaponization (template injection) means defensive action should not be delayed.

Remediation

Upgrade JetBrains IntelliJ IDEA to version 2026.1 or later, which patches the template injection flaw in the Copyright plugin. Organizations should prioritize developers who frequently download or clone third-party projects. In the interim, users can disable the Copyright plugin if it is not essential to their workflow, though this is a workaround rather than a fix. Verify patch availability through the official JetBrains website and apply updates through the IDE's built-in update mechanism or your organization's software distribution process.

Patch guidance

JetBrains has released version 2026.1 as the fixed version. Developers should apply updates through IntelliJ IDEA's Help > Check for Updates menu or download the latest version from jetbrains.com. Organizations managing multiple IDE deployments should use the IntelliJ IDEA update service or package management systems to roll out patches consistently. Test the update in a non-production development environment first to ensure no compatibility issues with existing plugins or projects.

Detection guidance

Monitor for unexpected processes spawned by IntelliJ IDEA (java.exe or intellij processes) that perform unusual system calls, network connections, or file modifications outside the project directory. Endpoint Detection and Response (EDR) tools should flag anomalous behavior from the IDE process. Code review of project configuration files (e.g., Copyright.xml or similar templates) for suspicious macro or template syntax can help identify malicious payloads before they execute. Log IDE startup parameters and plugin loading to detect unauthorized plugin installation or template overrides.

Why prioritize this

Although the CVSS score of 4.5 is relatively low, the vulnerability warrants prompt remediation due to its location in a development tool used by teams responsible for critical infrastructure and proprietary code. Developers are high-value targets for supply-chain attacks, and compromising the IDE directly undermines the security of the entire software development lifecycle. The requirement for user interaction (opening a project) is a control measure, but social engineering and repository compromise are common attack vectors.

Risk score, explained

CVSS 3.1 assigns a score of 4.5 (MEDIUM) reflecting: local attack vector (AV:L) with no network reachability; high attack complexity (AC:H) due to the need for user interaction and specific plugin configuration; no privileges required (PR:N); user interaction required (UI:R); impact scope unchanged (S:U); and low impact on confidentiality, integrity, and availability (C:L/I:L/A:L). The moderate score acknowledges that exploitation is feasible but not trivial, and impact is limited to the local system rather than network-wide propagation.

Frequently asked questions